Bayfield, WI (Northland's NewsCenter) - As calls came in to the Apostle Islands National Park Service of a green scum, visible from Cornucopia to Myer's Beach, officials raced to gather samples of the unusual occurrence.
"We had our blue–green algae expert look at it, and she confirmed that, indeed, it was a species of blue–green algae. We don't see this in Lake Superior; we don't see it in our northern lakes very often either," said Nancy Larson, DNR Lake Superior Water Quality team leader.
"...because the lake is not only cold, but it tends to have a lot of wave action," said Julie Van Stappen, of the Apostle Islands National Park Service, explaining why the algae bloom is so rare for the Great Lake.
More prevalent on warm, stagnant, inland lakes, where water has been enriched with nutrients, like nitrogen, blue–green algae—also known as 'pond scum'—is believed to have been fed by June's flood, which dumped sediment into Lake Superior at an unprecedented level.
"The currents of the lake tend to go from Duluth, and they flow toward the Apostle Islands," said Van Stappen.
The bacteria can produce cyanotoxins that remain in the lake for weeks—long after the algae bloom disperses. These toxins can pose numerous health risks for aquatic–bound life, including humans, if it comes into contact with the skin, or is ingested.
"...stomach upsets, diarrhea, people can also get some respiratory symptoms from it too, if they're inhaling the spray. Avoid having [your] dogs swim in it, because dogs will lick it off their fur," said Larson.
While the samples collected at Myer's Beach did not contain toxins, a sick eagle found in the beach's caves fueled officials' concerns for the safety of kayakers and campers, who often attain drinking water straight from the lake, through filtration methods.
"If it's not completely clear, don't filter it," said Van Stappen, emphatically.
And, with the unusual chain of weather the Northland has experienced this summer, the possibility of another bloom is too close for comfort.
"As we're seeing more of these storms, and as we're seeing warmer temperatures, we might see more problems with these kind[s] of algae. So, we should keep on the lookout for this, and people should be concerned about those impacts to the Great Lakes, and to Lake Superior," said Larson.
Drought in southern Wisconsin is currently fueling algae blooms in lakes once thought safe from the Cyanobacteria.
The Wisconsin DNR is urging the public to report any potential sightings of pea soup–like scum layers on Lake Superior to their headquarters, or to the Apostle Islands National Park Service.
WI DNR: (715) 635-4034 // (715) 685-2913
Apostle Islands Nat'l Lakeshore: (715) 779-3398, ext. 102